Liquid Codeine Major Reaction...... Anyone Else?

Some pain meds are not tolerated by individuals, whether they had wt loss surgery or not. I know my mom has had several surgeries over the years. She always tells them she gets sick on Demerol, and that's typically what's given post op at her hosptial. Each time they give it to her she gets sick, and she's not had any wt loss surgery.  Dave